571 research outputs found

    Effects of Non-Local Diffusion on Structural MRI Preprocessing and Default Network Mapping: Statistical Comparisons with Isotropic/Anisotropic Diffusion

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    Neuroimaging community usually employs spatial smoothing to denoise magnetic resonance imaging (MRI) data, e.g., Gaussian smoothing kernels. Such an isotropic diffusion (ISD) based smoothing is widely adopted for denoising purpose due to its easy implementation and efficient computation. Beyond these advantages, Gaussian smoothing kernels tend to blur the edges, curvature and texture of images. Researchers have proposed anisotropic diffusion (ASD) and non-local diffusion (NLD) kernels. We recently demonstrated the effect of these new filtering paradigms on preprocessing real degraded MRI images from three individual subjects. Here, to further systematically investigate the effects at a group level, we collected both structural and functional MRI data from 23 participants. We first evaluated the three smoothing strategies' impact on brain extraction, segmentation and registration. Finally, we investigated how they affect subsequent mapping of default network based on resting-state functional MRI (R-fMRI) data. Our findings suggest that NLD-based spatial smoothing maybe more effective and reliable at improving the quality of both MRI data preprocessing and default network mapping. We thus recommend NLD may become a promising method of smoothing structural MRI images of R-fMRI pipeline

    Time-Resolved X-Ray Diffraction Investigation of Superheating-Melting of Crystals under Ultrafast Heating

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    The maximum superheating of a solid prior to melting depends on the effective dimensionless nucleation energy barrier, heterogeneities such as free surfaces and defects, and heating rates. Superheating is rarely achieved with conventional slow heating due to the dominant effect of heterogeneous nucleation. In present work, we investigate the superheating-melting behavior of crystals utilizing ultrafast heating techniques such as exploding wire and laser irradiation, and diagnostics such as time-resolved X-ray diffraction combined with simultaneous measurements on voltage and current (for exploding wire) and particle velocity (for laser irradiation). Experimental designs and preliminary results are presented

    Poly[[tetra­aqua­bis­(μ3-5-carboxybenzene-1,2,4-tri­carboxyl­ato)tricadmium] tetra­hydrate]

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    There are three independent CdII ions in the title complex, {[Cd3(C10H3O8)2(H2O)4]·4H2O}n, one of which is coordinated by four O atoms from three 5-carboxybenzene-1,2,4-tri­carboxyl­ate ligands and by two water mol­ecules in a distorted octa­hedral geometry. The second CdII ion is coordinated by five O atoms from four 5-carboxybenzene-1,2,4-tri­carboxyl­ate ligands and by one water mol­ecule also in a distorted octa­hedral geometry while the third CdII ion is coordinated by five O atoms from three 5-carboxybenzene-1,2,4-tri­carboxyl­ate ligands and by one water mol­ecule in a highly distorted octa­hedral geometry. The 5-carboxybenzene-1,2,4-tri­carboxyl­ate ligands bridge the CdII ions, resulting in the formation of a three-dimensional structure. Intra- and inter­molecular O—H⋯O hydrogen bonds are present throughout the three-dimensional structure

    Plant diversity of Southeast Asia-II

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    The special issue of plant diversity in Southeast Asia will focus on the documentation of new discoveries in SE Asia. There are four global biodiversity hotspots in Southeast Asia. Although there are many plans to protect this rich biodiversity, however, the rich biodiversity in SE Asia is under threat due to economic development and population growth. There is a huge gap between our knowledge and biodiversity in SE Asia. During the last six investigations, many new taxa, including new species, new genera, have been discovered. This special issue will bring the rich but little known biodiversity to the public and protect them

    Diaqua­bis­{1-[(1H-benzimidazol-2-yl)meth­yl]-1H-imidazole-κN 3}dichlorido­cadmium hexa­hydrate

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    In the title complex, [CdCl2(C11H10N4)2(H2O)2]·6H2O, the CdII atom is located on a twofold rotation axis and is coordinated by two N atoms from two 1-[(1H-benzimidazol-2-yl)meth­yl]-1H-imidazole ligands and two water O atoms in equatorial positions and by two Cl atoms in axial positions, leading to an elongated octa­hedral environment. The two coordinating and two of the lattice water mol­ecules are also located on twofold rotation axes. In the crystal, complex mol­ecules and solvent water mol­ecules are linked through a complex inter­molecular N—H⋯O, O—H⋯N, O—H⋯O and O—H⋯Cl hydrogen-bonding scheme into a three-dimensional network

    (22E,24R)-5α-Ergosta-2,22-dien-6-one

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    In the title mol­ecule, C28H44O, two six-membered rings have regular chair conformations, while the six-membered ring containing the C=C double bond exhibits a distorted chair conformation. The five-membered ring adopts an envelope conformation. In the crystal, weak inter­molecular C—H⋯O inter­actions link mol­ecules into chains along the b axis. The absolute configuration was assigned to correspond with that of the known chiral centres in a precursor mol­ecule

    (22E,24R)-3α,5-Cyclo-5α-ergosta-22-en-6-one

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    In the title mol­ecule, C28H44O, the two six-membered rings have a chair conformation and the two five-membered rings haveenvelope conformations. The crystal packing exhibits no short inter­molecular contacts. The absolute configuration was assigned to correspond with that of the known chiral centres in a precursor molecule, which remained unchanged during the synthesis of the title compound

    (E)-N′-(4-Methoxy­benzyl­idene)benzohydrazide

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    In the title mol­ecule, C15H14N2O2, the dihedral angle between the benzene rings is 5.93 (17)°. In the crystal, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains propagating in [010]
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